fixed an error message, and added one if the path is invalid.
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index dd70122..2a3f53d 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -137,13 +137,14 @@
 		// Is $_FILES[$field] set? If not, no reason to continue.

 		if ( ! isset($_FILES[$field]))

 		{

-			$this->set_error('upload_userfile_not_set');

+			$this->set_error('upload_no_file_selected');

 			return FALSE;

 		}

 		

 		// Is the upload path valid?

 		if ( ! $this->validate_upload_path())

 		{

+			$this->set_error('upload_no_filepath');

 			return FALSE;

 		}